Isn the lack of a public access channel a violation of the free speech rights guaranteed by the First Amendment?
Not likely. For this to be a violation, the city must first create the “public forum” and then unreasonably deny your access to it. Even this is questionable because the courts appear to make distinctions related to government owned public forums versus privately owned public forums. If the channel does not exist, then the public forum has not been created and you have no right to claim a violation of free speech rights in a forum that does not exist. A public access channel is a public forum but ownership of that forum may determine what rights you have to use it. There is considerable case law that prevents franchise authorities and cable operators from removing a public access channel once it has been created. This might explain why many cities will not create a public access channel in the first place.